1. Field of the Invention
The present invention relates to image processing apparatus and method for automatically determining an optimum image recording condition in the image recording on the basis of characteristics of a paper and an ink.
2. Related Background Art
A paper, an OHP sheet, and the like can be mentioned as materials to be recorded in the printing, electrophotograph, ink jet, and the like. An ink, a toner, and the like can be mentioned as recording color materials.
Hitherto, as a recording and adjusting method in an image recording apparatus, as disclosed in Japanese Utility Model Application Laid-open No. 5-25872, there has been known a type such that a test print is performed to a part of the stacked paper and is detected and the detection result is fed back to the recording condition.
According to the above adjusting method, however, since a test output is previously performed to obtain an image output which is actually desired paper is wasted.
On the other hand, as disclosed in Japanese Patent Application Laid-open Nos. 5-80625 and 5-221051, there are apparatuses which detect characteristics of a material to be recorded and a recording color material without performing a test print and execute recording and adjustment.
However, even if the characteristics of the material to be recorded and the recording color material are previously known, presuming method and apparatus for presuming image reproducibility of a recording matter after the recording by using the characteristic values are necessary.
On the other hand, hitherto, as disclosed in Japanese Patent Application Laid-open No. 5-176166 and Japanese Patent Publication No. 6-26906, there is a method of presuming by using a theoretical expression of what is called Kubelka-Munk or the like.
The existing presuming apparatuses, however, have a problem such that an image reproducibility cannot be presumed with enough precision.
As an example about the presuming precision, the presuming apparatus of the Kubelka-Munk type will now be described.
The theory of Kubelka-Munk uses a light diffusion equation in which, with respect to the behavior of light in the recording matter, it is projected and approximated one-dimensionally, namely, in the direction of thickness of the recording matter.
Therefore, in an actual image having a three-dimensional structure, particularly, a recording matter without translation symmetry in the area direction, namely, in the plane direction perpendicular to the thickness direction of the area type half-tone recording, actual image, or the like, an optical dot gain effect or the like cannot be correctly introduced and a problem occurs in the presuming precision.
FIGS. 7A and 7B are diagrams showing such an optical dot gain effect. FIG. 7A shows the case where the incident light was diffused in the area direction. FIG. 7B shows the case where it was one-dimensionally handled. Gradations in those cases are set to 36% and 52%, respectively.
FIG. 8 is a graph showing an example of the relation between an area factor of the recording color material and the gradation in such two kinds of handling methods. It will be understood that the gradation in the one-dimensional handling is largely deviated from that of the three-dimensional handling method in its half tone.
Such a deterioration in presuming precision is not limited to the foregoing monochromatic gradation performance. In a color mixed image using a multi-color recording color material, such a deterioration also occurs with respect to the hue direction and causes a large problem from a viewpoint of the color prediction.